Hyperoxic therapy systems, methods and apparatus

ABSTRACT

The present invention provides systems, methods, and apparatus for applying a hyperoxic therapy delivery system to a patient; administering hyperoxic gas to the patient according to an oxygen dose-response model; and adjusting the administration of the hyperoxic gas to the patient based upon monitored parameters related to a condition of the patient. Numerous additional features are disclosed.

RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. PatentApplication Ser. No. 61/873,811 filed Sep. 4, 2013, and titled“HYPEROXIC THERAPY SYSTEMS, METHODS AND APPARATUS”, (Attorney Docket No.MBOS-002/L); and U.S. Patent Application Ser. No. 61/873,817 filed Sep.4, 2013, and titled “HYPEROXIC THERAPY SYSTEMS, METHODS AND APPARATUS”,(Attorney Docket No. MBOS-003/L), each of which is hereby incorporatedby reference herein in its entirety for all purposes.

FIELD

The present invention generally relates to hyperoxic therapy, and moreparticularly is directed to systems, methods and apparatus fordelivering hyperoxic therapy.

BACKGROUND

The hyperbaric medical establishment holds that hyperbaric oxygentherapy is not effective with “normal wounds” (i.e., wounds that willheal normally without special intervention). Despite this establishedposition, several studies have produced confounding results thatindicate hyperbaric oxygen therapy can produce both positive andnegative outcomes for the healing of normal wounds in both soft tissueand bone. A detailed review of the prior art indicates that there is noclear explanation or understanding as to when, how, and under whatconditions hyperbaric oxygen therapy can be beneficial in such cases.Thus, what is needed are systems, methods and apparatus that canconsistently produce beneficial outcomes using hyperoxic therapy overthe domain from normal pressure to hyperbaric pressure.

SUMMARY

The present invention provides systems, methods and apparatus foreffective beneficial use of hyperoxic therapy for enhancing the healingof normal wounds such as cosmetic, oral, hair transplant, and the likesurgery and for improving neurological conditions such as traumaticbrain injury, cerebral palsy, autism spectrum disorders and the like,when applied in appropriate doses.

In some embodiments, the present invention provides systems, methods andapparatus for applying a hyperoxic therapy delivery system to a patient;administering hyperoxic gas to the patient according to an oxygendose-response model; and adjusting the administration of the hyperoxicgas to the patient based upon monitored parameters related to acondition of the patient.

In some embodiments, the present invention provides a method. The methodincludes applying a hyperoxic therapy delivery system to a patient;administering hyperoxic gas to the patient according to an oxygendose-response model; and adjusting the administration of the hyperoxicgas to the patient based upon monitored parameters related to acondition of the patient.

In other embodiments, the present invention provides an alternativemethod. The alternative method includes determining an initial oxygendose-response model for a patient based upon the patient and a conditionto be treated; applying an initial oxygen dose to the patient in aninitial treatment session based upon the initial oxygen dose-responsemodel; reassessing the patient's condition periodically; adjusting theoxygen dose-response model to reflect the patient's reassessedcondition; and determining an adjusted oxygen dose based upon theadjusted oxygen dose-response model.

In yet other embodiments, the present invention provides a system. Thesystem includes a processor; a memory coupled to the processor andoperative to store instructions executable on the processor to determinean initial oxygen dose-response model for a patient based upon thepatient and a condition to be treated; indicate an initial oxygen doseto apply to the patient in an initial treatment session based upon theinitial oxygen dose-response model; receive data for reassessing thepatient's condition periodically; adjust the oxygen dose-response modelto reflect the patient's reassessed condition; and determine an adjustedoxygen dose based upon the adjusted oxygen dose-response model.

In still other embodiments, the present invention provides a breathinghood assembly. The breathing hood assembly includes an assemblyincluding a hood ring and a sealable tent portion, wherein the hood ringincludes a first portion and a second portion adapted to releasablyattach to an O-ring finish of the sealable tent portion; and a necksealring assembly including an elastic neck dam and a neckseal ring, whereinthe neckseal ring includes a first portion and a second portion adaptedto releasably attach to an O-ring finish of the neck dam. The hood ringis adapted to sealably engage the neckseal ring.

In yet still other embodiments, the present invention provides analternative breathing hood assembly. The alternative breathing hoodassembly includes a tent assembly including a hood ring and a sealedtent portion; and a neckseal ring assembly including a torso sealassembly and a neckseal ring. The hood ring is adapted to sealablyengage the neckseal ring.

In some other embodiments, the present invention provides a hyperoxicgas delivery system. The hyperoxic gas delivery system includes abreathing hood assembly; and a control unit coupled to the breathinghood assembly via an umbilical. The control unit is adapted to deliverhyperoxic gas to the breathing hood assembly via the umbilical atapproximately one atmosphere.

Numerous other aspects are provided. Other features and aspects of thepresent invention will become more fully apparent from the followingdetailed description, the appended claims and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of healing rate/quality versus oxygen treatment dosageaccording to some embodiments of the present invention.

FIG. 2 is a graph of healing rate/quality versus oxygen treatment dosagefor three different levels of tissue perfusion or tissue damage levelsat the wound site according to some embodiments of the presentinvention.

FIG. 3 is a flowchart depicting an example method of providing hyperoxictherapy according to some embodiments of the present invention.

FIG. 4 is a three dimensional graph depicting the operating ranges fortreatment parameter values of various prior art hyperoxic therapiesrelative to values for the novel hyperoxic therapy of embodiments of thepresent invention.

FIG. 5 is a flowchart depicting a second example method of providinghyperoxic therapy according to some embodiments of the presentinvention.

FIG. 6 is an exploded perspective view of an example hood assembly of ahyperoxic gas delivery system in accordance with embodiments of thepresent invention.

FIG. 7 is an exploded perspective view of an example torso collarassembly of a hyperoxic gas delivery system in accordance withembodiments of the present invention.

FIG. 8 is a perspective view of a first example securing system of ahyperoxic gas delivery system in accordance with embodiments of thepresent invention.

FIG. 9 is a perspective view of a second example securing system of ahyperoxic gas delivery system in accordance with embodiments of thepresent invention.

FIG. 10 is a block diagram of an example hyperoxic gas delivery systemin accordance with embodiments of the present invention.

FIG. 11 is a perspective view of an example hyperoxic gas deliverysystem in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

Inventive systems, methods and apparatus are provided for effectivebeneficial use of a novel hyperoxic therapy for enhancing healing ofnormal wounds, providing prophylaxis against development of conditionssuch as repetitive strain injuries, and providing more beneficialoutcomes in treating conditions such as cerebral palsy, autism spectrumdisorders, brain trauma, glomerulonephritis, and other conditions whenapplied in appropriate doses. The inventors of the present inventionhave determined that use of an oxygen dose-response methodology ofadministering and adjusting hyperoxic therapy provides such efficacy. Inother words, by treating patients based upon a hyperoxic dosage dictatedby a model that defines changing efficacious doses over time, beneficialresults can be consistently obtained. As used herein, the term “normalwounds” refers to wounds that would otherwise heal without exceptionalmedical intervention. Also as used herein, the term “hyperoxic gas”refers to a gas with a partial pressure of oxygen greater than that ofatmospheric air (e.g., PO2>0.20954 ATM), regardless of the pressure atwhich it is breathed (e.g., normobaric or hyperbaric). Dosage can bedefined in terms of the frequency of treatments, the partial pressure ofoxygen in inspired gas (PiO2), the duration of each treatment, and thenumber of treatments.

Further, the inventors of the present invention have determined that toohigh a dose of oxygen relative to the circumstances produces asuboptimal and in some cases, even a counterproductive outcome. Intoxicological terms, this type of biphasic dose-response relationship issaid to exhibit “hormesis” or to be “hormetic” in nature, characterizedby a low dose stimulation or beneficial effect and a high doseinhibitory or toxic effect. In other words, in some circumstances, lowdoses of oxygen can be as effective as, or even more effective than,higher doses, even when these higher doses represent clinical norms.According to embodiments of the present invention, as thepathophysiology of the wound site improves during the course of therapy,the dose of oxygen can be adjusted (e.g., reduced) to optimize and/ormaintain benefits. Thus, the present inventors have determined theefficacy of normobaric hyperoxia in the treatment of normal wounds suchas cosmetic, oral/dental, hair transplant, and the like surgeries;prophylaxis against development of repetitive strain injuries such ascarpal tunnel syndrome; neurological conditions such as traumatic braininjury, cerebral palsy, chronic traumatic encephalopathy, stroke and thelike; developmental disorders such as autism spectrum disorders;inflammatory conditions such as glomerulonephritis; and unaccustomedphysical use injury (e.g., delayed onset muscle soreness) when appliedin appropriate doses.

In some aspects of the present invention, a significant issue relativeto the practical application of low-dose oxygen was whether or notincreased pressure as provided by any type of whole-body hyperbaricchamber is necessary to achieve positive outcomes. While the hyperbaricmedical establishment maintains that pressure must be important becausesuch low doses of oxygen as those provided in mild hyperbaric oxygentherapy (e.g., 24% O2 at 1.3 ATA) cannot be conceived of as havingclinical benefit, the present inventors have determined the opposite istrue; namely that hyperoxia, no matter how low the dose, and notpressure is the critical element of the therapy. Except in a fewapplications, hyperbaric pressure is essential only to provide greaterinspired partial pressures of oxygen than can be achieved at normobaricpressure so that clinically effective doses of oxygen can beadministered as required. Note that the exceptions relate to bubbledisorders (e.g., decompression sickness, gas embolism) where hyperbaricpressure physically reduces gas bubble size according to Boyle's law andaccelerates resolution of the gas phase by concentrating the moleculesin a smaller volume.

The present inventors have further determined that after peak benefit isreached, greater doses of oxygen produce a progressively lower responsewhich ultimately falls below that of no hyperoxic therapy at all.Consequently, the oxygen dose-response curve 102 shown in FIG. 1, whichdepicts a graph 100 of healing rate/quality versus oxygen treatmentdosage, graphically expresses this hormetic relationship. The presentinventors have determined that the outcome of hyperoxic therapy for aparticular wound relates to the dose of oxygen delivered to that woundedtissue and not simply the gross, whole-body dose. Since oxygen not onlyhas beneficial effects but is a toxic agent in relative overdose, theparticular outcome of any hyperoxic therapy is the net result of thebeneficial and toxic effects of oxygen at the wound site.

In some embodiments of the present invention, the consequences of theabove determinations support the following conclusions. First,uncompromised wounds to a particular tissue can be treated optimallywith lower doses of oxygen than wounds to this same tissue where oxygendelivery has been compromised by such things as circulatory disruption,edema, and inflammation. Second, as events such as angiogenesis and thereduction in edema and/or inflammation occur at a wound site, localoxygen delivery will increase and the optimal oxygen dose for therapywill decline correspondingly. Thus, the oxygen dose-response curve 102will shift toward the left in the graph 100 of FIG. 1 over time ashealing occurs. This has been validated through clinical trials of themethods of the present invention in the treatment of autism spectrumdisorders.

A third conclusion drawn from the above states that where tissues haveinherently different perfusion rates and, therefore, oxygen deliveryrates, the tissue with the higher natural oxygen delivery rate will mostoften be optimally treated with lower doses of oxygen than othertissues. This determination provides the set of dose-response curves202, 204, 206 shown in the graph 200 of FIG. 2. In other words, FIG. 2illustrates a graph 200 of healing rate/quality versus oxygen treatmentdosage for three different levels of blood flow and three differentlevels of how compromised the tissue was at the wound site. Morespecifically, the curves 202, 204, 206 represent differently woundedtissues where the leftmost dose-response curve 202 is for the leastcompromised tissue with the greatest perfusion rate and the rightmostdose-response curve 206 is for the most compromised tissue with thelowest perfusion rate. In terms of the oxygen dose-response model, theoxygen dose-response shifts toward lower doses as the blood flow to thewound site increases (e.g., more oxygen is delivered) and as the woundheals. Note that while local oxygen consumption will be a factor andcould impose shifts in the curves for specific tissues, this fact doesnot change the basic nature of the relationships.

Turning to FIG. 3, example methods of the present invention aredescribed with respect to flowchart 300. In some embodiments, theinventive process of the present invention includes using a breathingapparatus (e.g., embodiments described below) or other medical device toenable a patient to receive hyperoxic therapy. Thus, some form of ahyperoxic therapy delivery system is initially applied to or put on thepatient (302). Example embodiments of delivery systems particularlyuseful for performing the hyperoxic therapies of the present inventionare described below, however, it should be understood that the methodsof the present invention are not limited to the particular deliverysystems described below. Hyperoxia is administered to the patient viathe delivery system in accordance with an oxygen dose-response model(304). In other words, for example, the delivery system provides thepatient with oxygen or other hyperoxic nitrogen-oxygen gas mix with afraction of inspired oxygen (FiO2) of approximately 30% to approximately100% and a fixed positive end expiratory pressure (i.e., the pressure inthe breathing device above ambient) in the range of approximately 6 cmH2O to approximately 10 cm H2O (304). This small increased pressure iswithin the normal atmospheric variation of ambient pressure due toweather. The treatments can be conducted at local (e.g., normal)atmospheric pressure, a nominal 1 ATA (atmospheres absolute). Whole-bodypressure chambers are not required and increased hydrostatic pressuresare not required. In some embodiments, for example, an initial startingdose would involve treatments of 90% FiO2 administered approximatelyonce per day for up to approximately five days per week for eight weekswith a treatment session duration in the range of approximately 30minutes to approximately 90 minutes. The dose will vary based upon thepatient and the condition. For example, the treatment plan (whichspecifies the initial dose) for a child with autism might be for aperiod of one year whereas the plan for an adult with an electivesurgery wound can be for a one week period.

As the therapy process progresses, particularly in chronic cases, theoxygen dose of the treatments (i.e., FiO2, duration, and/or frequency oftreatments) is adjusted (306). As noted above, as the therapy processprogresses the oxygen dose-response curve 102 (FIG. 1) generally shiftsto the left and the peak healing rate/quality occurs at a lower inspiredPO2.

In some embodiments, the adjustments will include a reduction in theFiO2, duration, and/or frequency of treatments in accordance with theoxygen dose-response model, to maintain effectiveness. Such adjustmentcan be based on assessment of monitored parameters and the parameterscan be selected based upon the condition being treated. For example, inthe case of autism, the monitored parameters can include the total andsub-scale scores of the Autism Treatment Evaluation Checklist developedby Bernard Rimland and Stephen M. Edelson of the Autism ResearchInstitutehttp://c.ymcdn.com/sites/membership.uhms.org/resource/resmgr/position_papers/autism_position_paper.pdfwhich is hereby incorporated herein by reference. The adjustments areapplied recursively to dynamically maintain the optimal healingrate/quality.

In the case of Traumatic Brain Injury (TBI), the monitored parameterscan include, for example, scores from the Immediate Post-concussionAssessment and Cognitive Testing (ImPACT® Applications) as described byLovell M R, Iverson G I, Collins M W, Podell K, Johnston K M, Pardini D,Pardini J, Norwig J, and Maroon J C, in the publication entitled“Measurement of symptoms following sports-related concussion:Reliability and normative data for the post-concussion scale,” Appl.Neruopsychol, 2006; 13:166-174. And at http://www.impacttest.com whichare both hereby incorporated herein by reference. Additionally oralternatively, the score from the Post-traumatic Disorder Check List(PCL) in its various forms including civilian and military by Weathers FW, Litz B T, Herman D S, Huska J A, and Keane T M, in the publication“The PTSD checklist: Reliability, validity, & diagnostic utility” whichwas a paper presented at the Annual Meeting of the International Societyfor Traumatic Stress Studies, San Antonio, Tex. in 1993 and available athttp://www.mirecc.va.gov/docs/visn6/3_PTSD_CheckList_and_Scoring.pdfwhich are both hereby incorporated herein by reference.

In the case of Cerebral Palsy (CP), monitored parameters can include,for example, scores from the Gross Motor Functional Measure (GMFM) byNordmark E, Jarnlo G B, and Hagglund G, described in the publication“Comparison of the Gross Motor Function Measure and Pediatric Evaluationof Disability Inventory in assessing motor function in childrenundergoing selective dorsal rhizotomy” in Dev Med Child Neurol, 2000;42:245-252, and available athttps://www.militarymentalhealth.org/PTSD_screening?utm_source=google&utm_medium=cpc&utmterm=ptsd&utm_content=ptsd&utm_campaign=ptsd which are both herebyincorporated herein by reference.

In the case of glomerulonephritis, monitored parameters can include, forexample, a measure of the level of serum creatinine as further explainedathttp://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/nephrology/kimay be used and is hereby incorporated herein by reference.

An example therapy process for acute cases, such as may occur duringaesthetic cosmetic surgery, can include an initial treatment with anoxygen dose that is relatively high (e.g., having a relatively longtreatment duration for example, in the range of approximately 60 to 90minutes) followed by a number of additional treatments (e.g., in therange of approximately two to nine) of relatively shorter durations(e.g., in the range of approximately 45 to 60 minutes). In acute surgerycases where only diminishment of swelling and bruising is desired forexample, one 90-minute treatment can provide sufficient results in someembodiments. In other embodiments, different therapy processes inaccordance with the present invention that include different parametersor parameter values can be used.

Although several aspects of embodiments of the present invention havebeen disclosed above with respect to the novel features of theinvention, it should be understood that there are numerous prior arthyperoxic therapies that can include one or more treatment parametervalues that may incidentally and/or temporarily overlap with the novel“adjusting low-dose oxygen” hyperoxic therapy of embodiments of thepresent invention. In an effort to better clarify the differencesbetween embodiments of the present invention and the prior art hyperoxictherapies, the following table and FIG. 4 are provided.

OXYGEN PARTIAL CONCEN- PRESSURE ABSOLUTE TRATION OF HYPEROXIC PRESSURE(% ) OXYGEN CONDITIONS THERAPY (ATA) (FiO₂) (ATM) TREATED ConventionalHBO₂ 2.0-3.0 100 Static FDA recognizes in the those conditions rangerecommended by the 2.00-3.00 Undersea and Hyperbaric Medical Society(UHMS) HBO₂ Therapy Comm. Off-label HBO₂ 1.5-2.0 100% StaticNeurological in the conditions; sports range injuries (based on1.50-2.00 empirical results); Lyme disease Mild HBO₂ 1.3 21%-28% StaticNeurological in the conditions range 0.27-0.36 Hospital-based 1.0 100%Static Resuscitation, emergency-care and at 1.00 major trauma,advanced-first-aid-based anaphylaxis, major oxygen therapy hemorrhage,shock, active convulsions, hyperthermia, and transient hypoxaemia (e.g.,pulmonary embolism) Home-and care- 1.0 90 ± 3% Static Increasingarterial facility-based oxygen in the PO₂ in COPD; therapy rangecontrolling 0.87-0.93 breathlessness in end-stage cardiac or respiratoryfailure, advanced cancer, or neurodegenerative disease“Adjusting-low-dose 1.0 30%-100% Adjusted Chronic oxygen” hyperoxic overthe neurological & therapy of embodiments range of other medical of thepresent invention 0.30-1.00 conditions such as inflammatory disorders;developmental disorders; enhanced healing in elective surgery;repetitive strain injury; unaccustomed use injury; prophylaxis againstrepetitive strain injury

As can be seen from the above table wherein each row represents adifferent type of hyperoxic therapy and the last row describesembodiments of the present invention, some of the prior art therapiesinclude treatment parameter values that incidentally and/or temporarilyoverlap with the values of embodiments of the present invention. Thiscan be more clearly seen in the three dimensional chart 400 depicted inFIG. 4. The area patterned in crosshatching corresponding to yellowcolor represents the treatment parameter value range for conventionalhyperbaric oxygen (HBO₂) treatment 402. The area patterned incrosshatching corresponding to purple color represents the treatmentparameter value range for off-label HBO₂ treatment 404. The areapatterned in crosshatching corresponding to orange color represents thetreatment parameter value range for mild HBO₂ treatment 406. The pointdenoted by a star represents the treatment parameter values forhospital-based emergency-care and advanced-first-aid-based oxygentreatment 408. The points denoted by four dots represent the treatmentparameter values for home-based and care-facility-based oxygen treatment410. The area patterned in crosshatching corresponding to green colorrepresents the treatment parameter value range for “adjusting low-doseoxygen” hyperoxic treatment 412 of embodiments of the present invention.

Even where prior art methods overlap with the treatment parameter valuesof embodiments of the present invention and/or the conditions beingtreated however, there are two very significant distinctions: (1) thetreatment parameter values of embodiments of the present invention areadjusted through a progression wherein the oxygen dose (i.e., eithertreatment frequency, treatment duration, and/or inspired oxygenconcentration (FiO2)) is reduced periodically according to the oxygendose-response model as compared to the static values in the prior arttherapies, and (2) where the pressure range overlaps, the treatedconditions are different and where the treated conditions overlap, thetreatments are conducted at normal atmospheric pressure and not underhyperbaric conditions in a whole-body chamber. Embodiments of thepresent invention provide a form of systemic hyperoxic therapy which isconducted at normobaric pressure without the need for a whole-bodypressure chamber. Unlike with other prior art systemic hyperoxictherapies, the apparatus used in the present invention to supply thehyperoxic gases and deliver them to the patient are suitable for use inprivate homes with the assistance of relatives or caregivers of thepatients, in care facilities with the assistance of their typical staff,and in physicians' offices with the assistance of nurses or technicians.For such assistance, specialized clinical training is not required.Simple basic training in how to safely and effectively use the equipmentto administer the hyperoxic therapy of the present invention inaccordance with the prescription of a physician is all that is required.

Prior art oxygen therapy (i.e., normobaric oxygen therapy) differs fromembodiments of the present invention. In such prior art therapy, oxygenis administered systemically for acute conditions in emergency medicaland advanced first aid situations for resuscitation, major trauma,anaphylaxis, major hemorrhage, shock, active convulsions, hyperthermia,and transient hypoxemia (e.g., pulmonary embolism). Oxygen is alsoadministered to firefighters suffering smoke inhalation and diverssuffering decompression sickness and/or gas embolism prior to theirreaching a recompression chamber. This therapeutic process is called“oxygen therapy.”

Oxygen, or much more commonly, now, gas from medical oxygenconcentrators, typically with an oxygen concentration of 90±3%, isadministered systemically in home and care facility settings to increasearterial PO2 in chronic obstructive pulmonary disease (COPD) and toalleviate breathlessness in end-stage cardiac or respiratory failure,advanced cancer, or neurodegenerative disease. This process is alsocalled “oxygen therapy,” though in dealing with breathlessness, it hasbeen shown that the actual partial pressure of oxygen may not beimportant.

The oxygen concentration of the gas breathed by the patient is afunction of the flow rate of oxygen, typically ranging from 2 to 15standard liters per minute (slpm), and the type of delivery deviceutilized. Such devices typically include a nasal cannula deliveringbetween 24-40% oxygen; a simple face mask delivering between 28-50%oxygen; an air-entrapment or Venturi mask delivering a gradedconcentration of oxygen up to 40%; a partial rebreathing mask deliveringfrom 40-70% oxygen; a tight-fitting non-rebreather mask delivering from60-80% oxygen; a humidified, high-flow nasal cannula delivering up to100% oxygen, so long as the patient breathes exclusively through hisnose. Depending on the reason for oxygen therapy, the therapy gas may bebreathed continuously for extended periods (e.g., days).

This type of “oxygen therapy” which also called “surface oxygen,” unlikeembodiments of the present invention, is not administered to enhancenormal wound healing including those from elective surgical procedures,repetitive strain injuries, and delayed onset muscle soreness; to healor permanently improve chronic conditions such as neurological injury,developmental disorders, and inflammatory disorders; or to prevent thedevelopment of pathological conditions such as repetitive strain injury.Embodiments of the present invention involved systemically administeringhyperoxic treatments (that are adjusted periodically) which areefficaciously used for all of these conditions. Consequently, there isno overlap in applications for embodiments of the present invention andprior art normobaric oxygen therapy. Since embodiments of the presentinvention use gas with an oxygen concentration ranging fromapproximately 30% to approximately 100% at 1.0 ATA, however, there ispartial overlap in the partial pressures of oxygen used for conventional“oxygen therapy” and embodiments of the present invention.

Prior art hyperbaric oxygen therapy (HBO₂) differs from embodiments ofthe present invention. Hyperbaric oxygen therapy involves the systemicadministration of hyperoxic gas in a whole-body pressure chamber at apressure greater than that of the normal ambient environment (i.e., >1.0ATA (atmospheres absolute)). The gas breathed ranges from 100% oxygen toair, the latter rendered hyperoxic because of the increased pressure inthe chamber. The partial pressure of oxygen (PO2) is equal to thefraction of oxygen in inspired gas (FiO2) multiplied by the absolutepressure in the whole-body chamber in ATA (PA). This equation can beexpressed as:

PO₂=FiO₂×P_(A)

HBO₂ may be divided into several categories related to the type ofwhole-body chamber utilized, the chamber pressure utilized, and theconditions treated. These different forms of HBO₂ are described andcontrasted with the therapy of embodiments of the present inventionbelow.

Three types of whole-body chambers are used for the administration ofHBO₂. These are multiplace chambers which can accommodate multipleoccupants and, for clinical use, have pressure ratings from 3.0 ATA forrectangular-cross-section chambers to 6.0 ATA or more forcircular-cross-section chambers; monoplace chambers which accommodateonly one occupant and commonly have a pressure rating of 3.0 ATA; andGamow bags or Gamow-bag equivalents which can have FDA clearance, forthe treatment of acute altitude sickness but have come to be used for ahyperoxic therapy called “mild hyperbaric oxygen therapy” (mHBO₂),commonly at a pressure of 1.3 ATA.

Multiplace chambers are compressed with air, and oxygen or anothertreatment gas is breathed by patients via tight-fitting demand maskswith an overboard dump (e.g., exhaled gas passes through an exhaustregulator and out of the chamber and into a receiver or out of thebuilding), or from flow-through hoods. The hood exhaust is also carriedout of the chamber and into a receiver or out of the building. It isimportant that exhaust gas from either masks or hoods is taken out ofthe chamber as an increasing oxygen concentration in a multiplacechamber would impose significantly increased risk of fire.

Monoplace chambers are typically compressed and flushed continuouslywith oxygen, and the patient breathes the chamber atmosphere without abreathing device. As a consequence, these chambers are designed,manufactured, operated, and maintained to strict safety codes andstandards so that they do not present an inordinate risk of fire.

Mild hyperbaric oxygen chambers are reinforced fabric, inflatabledevices often with a zipper closure, and with limited visibility intoand out of the chamber through relatively small window inserts. Theyhave been modeled after equipment of a sort that was originallydeveloped to manage acute altitude sickness (i.e., “Gamow bag,” so namedafter its inventor, Rustem Igor Gamow). These chambers typically have apressure rating of 1.3 ATA and are inflated and flushed with gas from anoxygen concentrator providing 24% to 28% oxygen. The patient usuallybreathes the chamber atmosphere. Such devices are not designed for themany off-label clinical applications of mHBO₂ for which they have cometo be promoted. Where they are cleared by the FDA, it is as beingsubstantially equivalent to the Gamow bag with an “indications for use”statement specifying treatment of acute mountain sickness. The FDArequirements for such devices do not necessitate that they meet any gaspurity standards or engineering safety standards for pressure vessels(which is how they are being used in m HBO₂).

Prior art conventional hyperbaric oxygen therapy differs fromembodiments of the present invention. Conventional HBO₂ is conducted inhospital-associated, dedicated clinical units using either multiplace ormonoplace hyperbaric chambers. Treatment pressures commonly range from2.0 ATA to 2.8 ATA and 100% oxygen is invariably the treatment gasbreathed by the patients. The treatments are conducted by speciallytrained chamber operators and a physician must be in attendance (i.e.,in close proximity throughout the treatments).

Primarily because of third-party reimbursement issues, these dedicatedclinics will only treat indications recognized by the Centers forMedicare & Medicaid Services (CMS). These are the applications, and onlythose applications, for hyperbaric oxygen therapy advocated by theUndersea and Hyperbaric Medical Society (UHMS). They currently consistexclusively of:

-   -   Air or gas embolism    -   Carbon monoxide poisoning/carbon monoxide poisoning complicated        by cyanide poisoning    -   Clostridial myositis and myonecrosis (gas gangrene)    -   Crush injury, compartment syndrome, and other acute traumatic        ischemias    -   Decompression sickness    -   Arterial insufficiencies        -   Central retinal artery occlusion        -   Enhancement of healing in selected problem wounds    -   Severe anemia    -   Intracranial abscess    -   Necrotizing soft tissue infections    -   Osteomyelitis (refractory)    -   Delayed radiation injury (soft tissue and bony necrosis)    -   Compromised grafts and flaps    -   Acute thermal burn injury    -   Idiopathic sudden sensorineural hearing loss        Chronic conditions treated over prolonged courses of therapy        (e.g., osteomyelitis, problem wounds) employ the same dose of        oxygen (i.e., static pressure-duration-frequency combination)        for all treatment sessions from the beginning of therapy to its        end. This has been the case from the inception of HBO₂ to the        present time.

Note that none of the indications advocated by the UHMS are normalwounds of any type; neurological injury; developmental or inflammatorydisorders; or prophylaxis to prevent the development of any pathologicalconditions. Consequently, there is no overlap in applications of priorart conventional HBO₂ and embodiments of the present invention. Sinceembodiments of the present invention use gas with an oxygenconcentration ranging from approximately 30% to approximately 100% atapproximately 1.0 ATA, there is also no overlap in the partial pressuresof oxygen used for conventional hyperbaric oxygen therapy andembodiments of the present invention.

Prior art off-label hyperbaric oxygen therapy differs from embodimentsof the present invention. Off-label HBO₂ is conducted in free-standingclinical units using either multiplace or monoplace whole-bodyhyperbaric chambers. Treatment pressures commonly range from 1.5 to 2.0ATA, though occasionally pressures as high as 2.4 ATA are used, and 100%oxygen is invariably the treatment gas breathed by the patients.Treatments are conducted by specially trained operators and a physicianmay or may not be in attendance.

These clinics are operated on a private-pay basis, and for the mostpart, are prepared to treat any condition for which there is somerationale and a patient is willing to pay. Common applications includeneurological injuries such as cerebral palsy (CP), stroke, and traumaticbrain injury (TBI); developmental disorders such as autism spectrumdisorders (ASD); sports injuries which are classified as normal wounds;inflammations such as Crohn's disease. In a very few cases, cosmeticsurgeons have monoplace chambers in their offices and use HBO₂ toenhance the healing of their surgical procedures. Given theseapplications, there may be overlap between the uses of off-label HBO₂and embodiments of the present invention. However, HBO₂ by definition isconducted in a whole-body chamber at increased pressure with PO2>1 atmwhile embodiments of the present invention are conducted at normalatmospheric pressure without the use of a whole-body chamber and withPO2≦1 atm. Further, treatments for chronic conditions (e.g.,neurological injuries, developmental disorders) in off-label HBO₂invariably employ a constant dose of oxygen (i.e., a staticpressure-duration-frequency) for the entire course of treatments (e.g.,all treatment session use the same dose of oxygen). There is nosystematic adjustment in dose, much less adjustments based on oxygendoes-response model, even from one course of treatments for a givencondition to subsequent courses of treatments for that same condition.

Prior art mild hyperbaric oxygen therapy differs from embodiments of thepresent invention. Mild HBO₂ is conducted on an exclusively off-labelbasis in patients'homes, physicians' offices, and in free-standingclinics. Treatment pressures are typically 1.3 ATA which is the maximumpressure rating of the device. Users are not required to have anyspecial training.

Common applications include neurological conditions such as CP, multiplesclerosis, TBI, and stroke; developmental disorders such as ASD; andsports injuries. The chambers are purchased or rented by the users, orservices are obtained through “clinics” on a private-pay basis. Coursesof therapy (e.g., treatment sessions) employ the same dose of oxygen(i.e., static pressure-duration-frequency) from start to finish.Embodiments of the present invention and mHBO₂ can overlap in thetreatment of a variety of neurological conditions. There is also overlapin PO2 at the low end range of embodiments of the present invention, butmHBO₂ is always conducted at a hyperbaric pressure while embodiments ofthe present invention is conducted at normobaric pressure with gaseshaving higher concentrations of oxygen than those typically used formHBO₂.

As mentioned above, embodiments of the present invention have someapplications in common with both off-label hyperbaric oxygen therapy andmild hyperbaric oxygen therapy. However, in addition to the differencesin treatment parameter values and the adjustments made in accordancewith the oxygen does-response model, there are very significantdifferences in the convenience, cost, and safety of off-label and mildhyperbaric oxygen therapy processes in comparison to embodiments of thepresent invention.

The cost of the monoplace or multiplace chambers and theirinstallations, specially trained staff, clinic facility, directphysician involvement, oxygen consumed, and chamber and facilitymaintenance in off-label clinics mean that the charge for treatments atsuch clinics are significant. As off-label hyperbaric clinics are notcommon, getting to them can require significant travel. In the best ofcases, given round trip travel, time for the patient to change out ofhis street clothes into clinic-provided attire (for fire safety),compression time, treatment time, and decompression time, treatments canconsume four hours a day or more, five days a week for the course oftherapy, typically 20 or 40 treatments costing on the order of $4,000 to$8,000, respectively.

Other issues involved in hyperoxic therapy conducted in whole-bodychambers at an HBO2 clinic include having to accommodate one's scheduleto that of the clinic's; confinement, with confinement anxiety andsometimes true claustrophobia as complications; limitation in activitiesover the course of treatment; chamber pressurization or compression totreatment pressure which necessitates that the patients equalize thepressure in their middle ears and sinuses or suffer discomfort, pain,ruptured blood vessels, and even ear drum rupture from barotrauma ifthis common complication is not effectively managed by the chamberoperator; chamber depressurization or decompression to surface pressurewhich subjects the chamber occupants to risk of serious barotrauma suchas gas embolism should gas be trapped in their lungs, particularlyduring events such as emergency decompression (e.g., because of a firein the chamber room); development of absorption atelectasis (e.g., lungcollapse resulting from oxygen absorption from alveoli with reduced orabsent gas exchange), which has been reported in the treatment of astroke case, as no provisions are now taken to prevent atelectasis intreatments conducted with breathing hoods or masks in multiplacechambers and none can be taken for treatments conducted in monoplacechambers, so long as the patients breathe the chamber atmosphere withouta breathing device. As a consequence of such factors, patient compliance(i.e., unwillingness to take the hyperbaric hyperoxic treatments) wasreported to be a major issue in a study of HBO2 for stroke.

Because of the hyperoxic environments in both oxygen-flushed monoplaceand air-compressed multiplace chambers, fire safety is an extremelyimportant concern in HBO2 of any sort.

In regards to the use of HBO2 for the enhanced healing of wounds fromelective surgical procedures, a multiplace chamber installation would bemuch too costly and space consuming. Thus, such an installation wouldhave to be based on monoplace chambers. Even then, these clinicalhyperbaric chambers are expensive to purchase and install (e.g., on theorder of $150,000-$200,000 for a single monoplace chamber, roompreparation, and essential liquid oxygen supply system), require officespace that is usually not available within a cosmetic surgery suite(e.g., a dedicated space of approximately 20′×10′ for a single monoplacechamber and additional space in the office or outside the building for asizable liquid oxygen supply system), and the employment of a qualifiedchamber operator. In view of the cost factors and the requirement forspace that would not usually be available in a physician's offices, theuse of HBO2 as an adjunct hyperoxic therapy for such purposes would notbe cost-effective and could rarely even be physically accommodated.

In comparison, the therapy of embodiments of the present invention iseasily accommodated and conducted when convenient in the homes ofpatients, the facilities where the patients are being cared for, or inthe offices of physicians where elective surgical procedures have beenperformed. As will be discussed below, the apparatus of the presentinvention is self-contained and can be used in a relatively small space(e.g., on the order of 25 square feet or less including space for acomfortable chair for the patient to sit in during treatment.). Duringtreatments, patients are free to engage in almost any activity possiblewithin the reach of the hood umbilical. These include watching TV,listening to music, playing games, reading, working on a computer, andwriting.

As whole-body pressure chambers with changes in pressure are notinvolved in embodiments of the present invention, there are norequirements for equalizing pressure in gas spaces such as the middleear and sinuses, no risk of decompression barotrauma such as gasembolism, and no confinement issues. Positive measures have also beentaken to prevent absorption atelectasis so it is not a risk factor forembodiments of the present invention.

In regards to risk of fire, since oxygen is involved, this is animportant issue, and proper fire safety guidelines must be followed atall times. With the system operating at only 1 ATA, however, there is noexacerbation of the problem by having pressurized hyperoxic gases inconfined spaces. There is also limited oxygen storage with liquid oxygencylinders as the gas source, and no oxygen storage when medical oxygenconcentrators are the gas source. These factors further minimize thehazard of fire. Consequently, despite the widespread use of liquidoxygen cylinders and, more recently, medical oxygen concentrators foroxygen therapy outside of medical establishments, oxygen-enriched fireincidents are rare.

In contrast to off-label hyperbaric oxygen therapy for overlappingapplications, the therapy of embodiments of the present invention isless costly, more convenient, less restrictive, and safer. Embodimentsof the present invention also incorporate dose adjustments to maintaintherapy effectiveness which HBO2 protocols do not.

In regards to cost, rental rates for the smaller mHBO2 chambers and thesystem of embodiments of the present invention are not greatlydifferent. The larger mHBO2 chambers are more expensive, however. Inpractical use, mHBO2 is much more confining and more limiting inactivities during treatments than the system of the present invention.

From a safety standpoint, embodiments of the present invention haveconsiderably less risk than mHBO2. A patient in an mHBO2 chamber cannotget out of the device on his own. He requires outside assistance.Consequently, should there be a failure of the gas supply for any reason(e.g., electrical power failure, oxygen concentrator failure, or supplyline disconnect), then an improperly supervised patient could die fromcarbon dioxide poisoning and/or hypoxia.

In contrast, as will be discussed below, the system of embodiments ofthe present invention includes a relief valve to provide room air flowinto the hood should the supply system fail. In addition, in embodimentswhere an oxygen concentrator is used as the gas supply source, a loudaudible alarm system is provided for detectable failures (e.g.,electrical power failure, low supply pressure, etc.).

Another safety issue in regards to mHBO2 chambers is structuralintegrity. As noted in the description of these chambers above, sincethey are regarded as substantially equivalent to the Gamow bag by theFDA, they are not required to meet any engineering safety standards for510(k) clearance. In order to be eligible for FDA 510(k) clearance, thenew device must exhibit roughly the same safety and effectivenesscharacteristics as the “predicate” device to which the new one is beingcompared. Not surprisingly, therefore, some mHBO2 chambers, inparticular one that actually does have FDA clearance, have failedmultiple times in service creating what the FDA has classified as a“life-threatening” incident.

With respect to elective surgical procedures, mHBO2 has no efficacy, andthe zipper bags utilized for mHBO2 lack adequate patient-friendlinessfor this market, even if the therapy did provide benefit.

In summary, mHBO2 involves treatments in confining, whole-body pressurechambers with limited visibility and little patient-friendliness.Compression to treatment pressure requires equalization of middle earand sinus pressures with operator mismanagement potentially leading todiscomfort, pain, and overt injury (e.g., ear drum rupture). As thechamber environment is breathed by the patient without a deliverydevice, there can be no provision for the prevention of absorptionatelectasis. The chambers, themselves, are subject to structural failurewhich could lead to life-threatening incidents, and no safety featuresare built in to mitigate against obvious failure situations. The processof mHBO2 has no provision for change of dose correlated with patientprogress.

In contrast, therapy in accordance with embodiments of the presentinvention is conducted at normal atmospheric pressure and does notrequire compression. The system is not confining and permits patients toengage in a great variety of routine activities. Because the systemutilizes only a very small pressure to prevent absorption atelectasis,there is no risk of injury due to catastrophic pressure boundaryfailure. Lastly, the process of embodiments of the present inventionincludes provision for dose changes in response to patient progress tomaintain treatment effectiveness.

Turning now to FIG. 5, a flowchart depicting a second example method 500according to embodiments of the present invention is depicted. Aninitial oxygen dose-response model is determined for a patient basedupon the patient and the condition to be treated (502). The oxygendose-response model can include a curve that identifies an optimaloxygen dose for maximal healing rate and quality. The oxygen dose can bedefined in terms of pressure (e.g., inspired PO2 within a predefinedenvelope of absolute pressure (ATA), oxygen concentration, and oxygenpartial pressure ranges), duration (e.g., length of the treatmentsession, and frequency (e.g., number of treatment sessions per timeperiod, for example number per week, number per month, etc.).

The initial dose is applied to the patient in an initial treatmentsession (504). A reassessment of the patient's condition is madeperiodically based upon a schedule determined to optimize treatment ofthe condition (506). The oxygen dose-response model is adjusted toreflect the patient's current condition and an adjusted oxygen dose isdetermined based on the adjusted oxygen dose-response model (508). Adetermination is made whether further treatment sessions will providefurther healing (510). For example, if the treated condition is healed,if normal levels of monitored indicators are achieved, or if no furtherimprovements have been achieved since a prior determination, theendpoint of treatment is deemed to have been reached. If furthertreatment sessions will provide further healing, the method 500 returnsto assessing the patient's condition (506). If further treatmentsessions will not provide further healing, the method 500 ends.

The hyperoxic therapy delivery system of embodiments of the presentinvention is one which permits the slightly-greater-than ambientpressure within the system to be comfortably maintained and toleratedover the course of the treatment. Because a conventional continuouspositive airway pressure (CPAP) mask which provides the requisite gasdelivery capability must be strapped securely to the face of thepatient, it is not physically ideal for the administration of theinventive hyperoxic therapies described above, particularly in the caseof children and patients with facial wounds. Likewise, the cost, spacerequirements, and operational requirements including gas supply,staffing, risk, and maintenance of multiplace hyperbaric chambers, andeven monoplace chambers, a Gamow bag, or any of the other soft-skinnedhyperbaric chambers, may make hyperoxic therapy administered using achamber impractical. Consequently, in some embodiments, the presentinvention can include the use of a novel breathing hood which includesenhanced gas flow distribution within the hood and enhanced ease-of-usefeatures such as hood application, securing, and removal.

Removing the need for close facial contact (such as with a CPAP mask)not only makes the hyperoxic gas delivery system of the presentinvention more comfortable, but also improves compliance in patients,such as autistic spectrum (ASD) patients, and eliminates problems andcomplications for patients in the cosmetic, hair transplant, and dentalsurgery sectors who have had facial or head procedures.

Compared to conventional breathing hoods, the hyperoxic gas deliverysystem of the present invention has improved comfort, an improved gasflow pattern within the hood to enhance carbon dioxide (CO2) clearanceand minimize internal temperature buildup, includes a fail-to-safetyinward opening relief valve for loss or failure of gas supply, improvesthe ease of putting the device on and taking it off the patient, andoverpressure prevention. The hood assembly of the present invention isdesigned so that the clear flexible plastic head cover (hood/tent), theelastic neck dam and the torso collar each incorporate molded O-ringfinishes which allow them to be replaceable, and the ring elements canbe sterilized/disinfected and reused from patient to patient.

In some embodiments, the hyperoxic gas delivery system of the presentinvention includes six main elements. Turning to FIG. 6, the first mainelement is the hood assembly 600 which is depicted in an explodedperspective view. The hood assembly 600 includes a sealed “head tent”that covers the head of the patient creating the enclosed environmentfrom which the patient breathes the hyperoxic gas. The hood assembly 600may include two parts. The first, an over-the-head portion 602, can beformed from soft, clear plastic head tent 604 which takes the generalshape of a bell jar/bucket when fully inflated. At the bottom of theover-the-head portion 602 is a hood ring 606 with internal interruptedthreads 608 and external lugs 610. The hood ring 606 of theover-the-head portion 602 can include two parts, an inner ring 612 whichhas a circumferential O-ring groove 614 on its outer diameter that willengage with a circular molded O-ring finish 616 on the head tent 604 ofthe over-the-head portion 602. The O-ring finish 616 of the head tent604 is sealingly trapped and secured when the second part of the hoodring 606, an outer ring 618 is placed over the inner ring 612 andsecured with removable distributed (e.g., evenly spaced about thecircumference) pins (not shown) which engage with the inner ring 612. Inalternative embodiments, the distributed pins may be replaced withalternative fixings such as screwed elements, twist-locks, or some otherfixing.

The second part of the hood assembly 600 is the neckseal ring assembly620. The neckseal ring assembly 620 can include an upper part 622 and alower part 624 that together capture and securely hold a neck dam 626. Agroove 628, sized and shaped to accommodate a non-circular molded O-ringfinish 630 of the neck dam 626 (and torso collar sleeves (not shown)) isprovided in the lower part 624 of the neckseal ring assembly 620. Insome embodiments, the upper part 622 of the neckseal ring assembly 620has interrupted threads 632 on its outside diameter that engage with theinterrupted threads 608 on the inside diameter of the hood ring 606, andexternal lugs 634 and tabs 640. The lugs 634 with finger holes 636 andmarkings (not shown) are positioned to guide the caregiver/technicianwhen fitting and removing the hood assembly 600.

The lugs 610, 634 are provided in pairs, one pair on each side of theouter circumference of the hood ring 606 and neckseal ring assembly 620.One lug 610 of each pair is on the hood ring 606, the other lug 634 ofeach pair is on the neckseal ring assembly 620. When the hood ring 606is placed on to the neckseal ring assembly 620, one pair of lugs 610,634 will be together (e.g., immediately adjacent to each other or incontact), the other pair will be separated. Squeezing the separated pairof lugs together rotates the hood ring 606 on the neckseal ring assembly620 engaging the interrupted threads 608, 632 and locking the two rings606, 620 together. This rotation also separates the originally pair oflugs used to orient the hood ring 606 and the neckseal ring assembly 620during initial placement on the patient.

To unlock and remove the over-the-head portion 602, the now separatedpair of lugs 610, 634 is squeezed together, thus rotating the hood ring606 in the opposite direction and unlocking it from the neckseal ringassembly 620. Note that in some embodiments, the lugs 634 on theneckseal ring assembly 620 can extend upward (e.g., have an increasedthickness compared to the lugs 610 on the hood ring 606) such that whena pair of lugs 610, 634 are squeezed together, each lug 634 on theneckseal ring assembly 620 serves as a positive stop for thecorresponding lug 610 on the hood ring 606, ensuring that theinterrupted threads 608, 632 are properly aligned (or misaligned) andfully engaged (or fully disengaged). In alternative embodiments, eachpair of lugs 610, 634 is adapted to align vertically when squeezedtogether to provide a positive indication that the interrupted threads608, 632 are properly aligned (or misaligned) and fully engaged (orfully disengaged).

In operation, this closure also activates an “O”-ring seal located in agroove 638 provided on the outer circumference of the neckseal ringassembly 620 immediately below the interrupted thread 632. This O-ringseal prevents gas leakage from the hood assembly neckseal joint betweenthe hood ring 606 and the neckseal ring assembly 620. In this way, thehood assembly 600 is either securely locked in place, ready for use, orunlocked for removal.

The tabs 640 on the neckseal ring assembly 620 include “L” or “J” shapedslots which are used in securing the hood assembly 600 so it does nottend to float up on the patient's head when in service.

In some embodiments, there are alternative approaches to preventing gasleakage from the neckseal ring assembly-patient interface duringtreatment. The first uses a conventional elasticized neck dam (similarin function to the neck dam in the breathing hood manufactured by AMRONInternational, Inc. of Vista, Calif.). In contrast to prior art neckdams, the neck dam 626 of embodiments of the present invention isdesigned to be replaceable and the outer edge is finished with anon-circular molded O-ring 630 compatible with the non-circular groove628 provided in the lower part 624 of the neckseal ring assembly 620.The neck dam 626 of the present invention is compressionally engaged inthe non-circular O-ring groove 628 when the upper part 622 and lowerpart 624 of the neckseal ring assembly 620 are brought together andsecured by screwed elements (not shown) or, in alternative embodiments,fixings such as twist locks, spring clips, or other fasteners. Anopening in the center of the elastic neck dam 626 is cut to size to sealsecurely around the patient's neck and prevent gas leakage. To helpprovide a secure seal on the neck and reinforce the neck dam materialagainst tearing, a series of concentric circumferential O-rings aremolded into the neck dam. When used properly, these seals have a longlife.

Turning now to FIG. 7, a second, alternative embodiment uses a torsoseal or torso collar assembly 700 that is open to the full insidediameter of the lower part 624 of the neckseal ring 702 and does nothave any elements that fit tightly around the neck (e.g., no neck dam626 as in the embodiment of FIG. 6). Rather, this alternative embodimentincludes parts that effectively seal the over-the-head portion 602around the patient's upper chest, upper back, and shoulders. One part isa molded torso collar 704 which is finished with a non-circular moldedO-ring finish 706 which adapted to engage with the non-circular O-ringgroove 628 on the lower part 624 of the neckseal ring 702.

The torso collar 704 is highly compliant and conforms to the shape ofthe patient's upper torso. Extending from the inside opening of thetorso collar 704 is a flexible sleeve 708 that ends in the non-circularmolded O-ring finish 706 that can be inserted into and retained by thenon-circular O-ring groove 628 provided in the lower part 624 of theneckseal ring 702. The non-circular molded O-ring finish 706 of thetorso collar 704 is compressionally engaged in the non-circular O-ringgroove 628 when the upper part 622 and lower part 624 of the necksealring 702 are brought together and secured by screwed elements (notshown) or, in alternative embodiments fixings such as twist locks,spring clips, or other fasteners.

After the torso collar 704 is lowered over the patient's head (with theneckseal ring 702 up) and is resting on his shoulders, a two-piecesecuring collar 710 as shown in FIG. 7, is put over the torso collar 704to hold it snuggly in place and ensure retention of the seal against thepatient's skin. The securing collar 710 is in turn held in place by ahood assembly harness. The over-the-head portion 602 (FIG. 6) is thenput in place and sealed by rotating the hood ring 606 on the necksealring 702 of the torso collar assembly 700 as above.

The torso collar assembly 700 is specifically designed for those, suchas cosmetic surgery patients, who cannot tolerate anything tight passingover the face or head, or being around the neck. In some embodiments, apadded collar (not shown) in the form of a circular tube joined, forexample, with Velcro™ and shaped like a “donut” can be opened out sothat it can be placed around a patient's neck. The padded collar can befilled with liquid gel, fine beads or air so that it readily conforms tothe shape of the torso collar 704 resting on the patients upper torso.In some embodiments, the padded collar can be placed in between thetorso collar 704 and the securing collar 710 and can be used to provideadditional downward pressure on the torso collar 704 to affect a seal.In some embodiments, an optional support collar 712 can be placed overthe head and on to the shoulders to support and spread the load andensure the torso collar assembly 700 can be fitted comfortably to thewidest possible of range of subjects.

In some embodiments, three service ports 714, 716, 718 are provided inthe neckseal ring assembly 620 and neckseal ring 702 respectively of thetwo types of sealing assemblies, one each for the gas supply 716 andexhaust 718 hoses, one for the hood assembly mounted inward-openingrelief valve 714. These service ports 714, 716, 718 are located in thefront (i.e., face side) of the neckseal ring assembly 620/neckseal ring702 immediately below the mouth and nose of the patient. Theinward-opening relief valve 714 lifts in the case of low pressure in thehood caused by a failure of the primary gas supply, and will allowambient air to flow into the hood assembly.

The service ports 714, 716, 718 are covered by a cowling 720 that servesat least three purposes: (1) to protect the service ports 714, 716, 718mechanically; (2) to help prevent contamination from patient-generatedsources such as spittle; and (3) to impose directionality to the hoodassembly gas circulation. Directionality of gas flow is achieved bymeans of shaped compartments within the cowling 720 that are finishedwith radiused ends and divided by a centrally located internal bulkheadin the cowling 720 that separates the incoming gas flow paths from theexiting gas flow paths. This gives directionality to the gas circulatingwithin the hood assembly, forcing it to flow in one direction around thepatients head to exhaust on the other side. In this way, acircumferential flow pattern is established within the hood assembly toensure that CO2, as well as excess heat and moisture are carried away tooptimize patient comfort and safety. The cowling 720 additional helps toavoid irritation and drying of the patient's eyes by preventing theincoming gas from flowing directly into the patient's face. In someembodiments, on the underside of the neckseal ring 702, the inwardopening relief valve, supply, and exhaust service ports 714, 716, 718are finished in male spigots. Each of the supply 716 and exhaust 718spigots are threaded to engage with the female threaded nut and ferruleterminations on an umbilical (not shown). The threads can be differentto prevent inadvertent cross-connection.

Unlike conventional breathing hoods currently used to deliver oxygen topatients in multiplace hyperbaric chambers which are intended to bedisposable, in some embodiments, a feature of the hood assembly of thepresent invention is reusability, longevity and reliability in service.This is achieved in two ways: the male/female locking parts of the hoodassembly are durable and tolerant to normal wear and tear, and the soft,“consumable” elements of the hood assembly such as the elasticized neckdam 626, the clear plastic head tent 604, and the torso collar 704, arerelatively inexpensive and easily replaceable by a technician orcaregiver/parent through the use of the two-part retaining rings 606,620, 702.

The more permanent parts of the hood assembly 600 such as the necksealring 702 and hood ring 606 and the securing collar 710, on the otherhand, can be taken apart for cleaning and disinfection in order tomaintain general cleanliness or in preparation for use by new patients.In this way, reusability, reliability and longevity in service areprovided.

In some embodiments, when in use with a slightly positive pressureinside it, the hood assembly 600 may tend to ride up on the patient'shead. Thus, the present invention can include a securing mechanism tohold down the hood assembly 600 and prevent it from bothering thepatient. The hood assembly 600 can be secured using one or moreapproaches as described below. These approaches are fully adjustable andcan be employed based on the type and size of the patient. For smallchildren, additional shoulder padding can be provided to ensure that thehood assembly is comfortable to wear. Note that the securing mechanismattaches to the neckseal ring assembly 620 (or neckseal ring 702) sothat the neckseal ring assembly 620 (or neckseal ring 702) can be fittedand comfortably secured to the patient before the over-the-head portion602 is placed on the patient.

In some embodiments, a first example securing system 800 is providedthat uses balls 802 (e.g., approximately 25 mm in diameter) onadjustable lengths of elasticized cords and/or suspenders 804 (called,“bungee-balls”) that individually fit into shaped slots in each of thefour tabs 640 (FIGS. 6 & 7) positioned approximately ninety degreesapart on the circumference of the neckseal ring assembly 620 andneckseal ring 702. The suspenders 804 can include fasteners 806 (e.g.,clips, hooks, snaps, loops, etc.) at the end opposite the balls 802 tosecure to the patient's clothing or studs 722 on the securing collar710. This arrangement provides a snug but not tight (e.g., notuncomfortable or restrictive) tie-down that has passive automaticadjustability when the patient changes body position. Once the necksealring assembly 620 or neckseal ring 702 is in place on the patient with aneck dam 626 or a torso collar 704, the four balls 802 are fitted intotheir respective slots in the tabs 640 on the neckseal ring assembly 620or neckseal ring 702 and secured to the patients clothing or the studs722 on the securing collar 710. Then, when the hood ring 606 is placedon the neckseal ring assembly 620 or neckseal ring 702, because of thenature of the slots and the size of the balls 802, the latter arephysically locked in place and cannot be released until the head tent604 is removed.

This design provides a significant convenience and safety feature thathelps ensure the hyperoxic gas delivery system is properly securedbefore treatment and remains in place while the unit is in use. Asdepicted in FIG. 9, in some embodiments, a second example hood assemblysecuring system 900 can include a loose-fitting, adjustable over-jacket902 similar to the brightly colored safety jackets worn by many workers.To counter the natural lift that comes when the hood assembly is inservice, the ball 802 and suspenders 804 are attached to thisover-jacket which is fitted with small weighted inserts that arestrategically placed to optimize comfort and ensure the weight is evenlydistributed around the hood assembly neckseal ring assembly 620 orneckseal ring 702. As useful, shoulder pads can be fitted to providecushioning 904 between the shoulders and the hood assembly neckseal ringassembly 620 or neckseal ring 702.

In some embodiments, four individually fitted adjustable, elasticizedsuspenders as shown in FIGS. 8 and 9 finished with ball 802 end fittingsas discussed above may be used to secure the hyperoxic gas deliverysystem. Each suspender can be 2-inches wide and fitted with standardsuspender fasteners 806 at the bottom end designed to attach to theover-jacket 902 or alternatively directly to the patient's waistband ofa skirt or pants including those of typical hospital scrubs and gowns.This method of fitting minimizes contact with the torso that somepatients, such as those who have undergone breast or abdominal surgery,may not tolerate well.

The hyperoxic gas delivery system of the present invention is designedto go over the head of patients without coming into contact with thehead and/or face. The underside of the neckseal ring assembly 620 orneckseal ring 702 is designed to sit on the shoulders and has wide flatsurface that prevents point loads and ensures any pressure (weight) isdispersed over a wide area rather than concentrated. For very smallchildren, a support collar 712 can be provided to interface with theunderside of the neckseal ring 702, to reduce the effective opendiameter of the neckseal ring 702 and maintain good contact with theshoulders, thus helping to avoid any physical discomfort. The supportcollar 712 is designed so that it can conform to the contour of theupper torso and shoulders front to back but is stiff enough laterallyacross the shoulders to support the hood assembly neckseal ring 702 evenwhen it is only making partial contact with the patient's shoulders.This is achieved by creating a material sandwich with center stiffeningusing either corrugation or simple straw-like tubular elements. The topof each pad includes a Velcro™ finish that will attach to a Velcro™strip applied to the underside of the hood assembly neckseal ring 702.In this manner, simple systems are provided that are highly adjustableto fit a wide range of patients, and practical for use even on difficultor non-compliant patients.

The inventors recognize that the hyperoxic gas delivery system of thepresent invention may be used with certain types of patients who, due tothe nature of their condition, such as autism spectrum disorder (ASD),may be inherently less compliant and difficult to manage. To providedistraction and fun for such patients, soft, translucent, and colorful,covers and/or gels that will fit over or attach to the head tent 604(FIG. 6) and impart a variety of themes such as a space helmet orcartoon characterizations can be provided as an option. The material ofmanufacture will ensure these covers will naturally adhere to the clearplastic material of the head tent 604 without need for adhesive, thusalso be easily removed and reusable.

Turning now to FIG. 10, the hyperoxic gas delivery system control unit1000 provides for control of all functions of the hyperoxic gas deliverysystem using a clearly labeled panel 1002. In one embodiment usingliquid cylinder storage oxygen is turned on and off with a coveredfail-to-safety switch 1004. System activation is achieved by lifting theswitch cover and toggling the switch 1004 to the open position whichbrings oxygen flow to the neckseal ring assembly 620 (or neckseal ring702). The over-the-head portion 602 is fitted to the neckseal ringassembly 620 after oxygen is on-line and removed before oxygen flow isshut-down. Shut-down is by a single action—just closing the cover. Inother embodiments, the switch 1004 actuates a concentrator 1006 whichbrings hyperoxic gas on line to the neckseal ring assembly 620 (orneckseal ring 702). The over-the-head portion 602 is fitted to theneckseal ring assembly 620 (or neckseal ring 702) after oxygen ison-line and removed before oxygen flow is shut-down. There is a gauge1008 which shows pressure in the hood assembly 600 during all stages ofthe respiratory cycle. A rotameter 1010 (e.g., flow meter) is providedto show the flow-rate into the hood assembly 600 at all times. Flow rateis set by adjusting the rotameter 1010 or selecting the appropriatecontrol valve settings on the liquid oxygen storage cylinders or oxygenconcentrator flow meters 1012. A pre-set back-pressure valve 1014 insidethe hyperoxic gas delivery system control unit 1000 controls the hoodassembly exhaust pressure, and thus internal pressure. An overpressurerelief valve 1016 is located in the supply circuit that will open andprevent the hood assembly 600 from being over-pressurized in the highlyunlikely event of a failure in the exhaust circuit. An in-lineparticulate filter 1018 on the exhaust side protects a back-pressurevalve 1014 from any excess moisture or particulates coming from the hoodassembly 600. The back-pressure valve 1014 is set at a fixed pressureranging from approximately 6 cmH2O to approximately 10 cmH2O whichproduces a greater functional residual capacity (FRC) in the patient'slungs and helps to ensure that an adverse pulmonary effect known asabsorption atelectasis (i.e., lung collapse due localized oxygenabsorption) will not occur when the patient is breathing hyperoxicgases. Data in the published literature has established that a residualpressure of 6 cmH2O is the minimum value needed to prevent atelectasis.Atelectasis is a safety concern since it has been shown to occur inpatients breathing hyperoxic gases at both normobaric and hyperbaricpressures.

The hyperoxic gas delivery system storage cabinet 1100 as shown in FIG.11 houses all of the elements necessary to operate the system. Theseinclude the hyperoxic gas delivery system control unit 1000 and panel1002, the gas supply source 1102, and an umbilical 1104. It alsoprovides storage space for the hood assembly 600 and the umbilical 1104when not in use. The cabinet 1100 can be designed to look like a pieceof furniture, presented in either traditional or contemporary styles tobe suitable for use in a home or professional office. These options helpensure that the cabinet 1100 fits reasonably well into any decor. Thecabinet 1100 can be split into several separate compartments, each ofwhich can be independently lockable to ensure equipment can be kept safeand secure while not in use. In some embodiments, the lower compartmentaccommodates liquid gas storage cylinders with full width double doorsto permit easy handling and exchange. A removable horizontal bracket(i.e., stretcher) can be provided for structural support and to securethe cylinders in an upright position during normal use. In someembodiments, the hyperoxic gas is supplied from an oxygen concentratorand the lower compartment is used to house and protect the concentrator.A gas connection manifold can be located on the inside rear wall of thelower section to connect the oxygen source to the hyperoxic gas deliverysystem control panel 1002.

In some embodiments, the upper section of the cabinet 1100 contains thehyperoxic gas delivery system control panel 1002 and a storage spacewith a drop-down door which can also be used as a writing/work surface.The height of the storage space provides secure storage for the hoodassembly 600, spare parts (e.g., neck dams), and the hyperoxic gasdelivery system control panel.

The supply and exhaust umbilical 1104 (i.e., the supply and exhaust gashose assembly) connects the hood assembly 600 to the hyperoxic gasdelivery system control panel 1002. The umbilical 1104 can be embodiedas a simple twin-hose assembly contained in a sleeve. The large-boreflexible hoses utilized ensure that the umbilical 1104 can be made intovirtually any reasonable length to permit the patient to move freelywithin an area determined by the caregiver. This can be an importantcompliance factor for ASD patients. In alternative embodiments, theumbilical 1104 may include a hose-in-hose (e.g., concentric) format inwhich a larger bore outer hose contains a smaller bore inner hoseeffectively forming a single hose umbilical which is easier to handleand store. For example, the outer hose can serve as the exhaust whilethe inner hose serves as the supply, each having its own end connectorthat will engage with single gas supply/exhaust spigot on a modifiedneckseal ring.

The gas supply and exhaust pipework from the hyperoxic gas deliverysystem control panel 1002 is terminated inside an inset “locker” spaceprovided in the cabinet 1100 and located to allow easyconnection/disconnection of the umbilical 1104. A circumferentialsupport bracket or self-winding reel located inside the locker allowsthe umbilical 1104 to be coiled and stowed securely. This ensures thetreatment area can be kept tidy and the umbilical 1104 protected fromdamage when not in use. The locker door can be notched to allow it to beclosed while the umbilical 1104 is deployed.

In some embodiments, the flow of gas used by the hyperoxic gas deliverysystem in operation is on the order of approximately 20 to approximately30 SLPM (standard liters per minute) provided by oxygen concentratorsand/or liquid cylinders. In some embodiments, this kind of demand can bemost effectively served from a liquid source or an oxygen concentratorrather than a compressed-gas source (i.e., high pressure cylinders).Liquid and/or concentrator based oxygen supply systems designed andapproved for home or physician office use are available in a number ofsizes. For example, liquid oxygen supply systems provided by CAIRE® andPuritan Bennett and/or oxygen concentrators such as those manufacturedby Chart Industries can be utilized. Because of the regulatorylimitations on oxygen supply volume (i.e., <3,000 SCF) without specialsafety provisions unlikely to be found routinely in either a home or aphysician's office, the possibilities for manifolding cylinders tomaximize service life between refills are limited. With any industrialor medical gas application it is desirable to minimize the frequency ofcylinder refills. The travel time and labor involved in refills can bethe most expensive elements in the cost. The Liberator 45 modelmanufactured by CAIRE®, a Chart Industries Company, provides anefficient option for storing liquid oxygen. These cylinders have beendesigned for routine home use and can be easily be manifolded together.To facilitate handling on-site, each cylinder can be mounted on a rollerbase.

As described above, oxygen dose (e.g., a function of treatment duration,oxygen partial pressure, and frequency) is a primary factor in achievingthe optimal response to therapy. This has been demonstrated in ongoingASD trials where adjusting dose has effectively kept progress movingforward when it became suboptimal. Further, neurological conditions, ingeneral, respond better to lower partial pressures of oxygen when beingtreated with hyperbaric oxygen therapy. This is a function of the veryhigh blood flow to the brain and the sensitivity of that organ to themetabolic and other disruptions relatively high doses of oxygen canproduce.

Even further, some neurological conditions such as Alzheimer's,particularly in its early stages, may be more effectively managed atnormal atmospheric pressure with oxygen concentrations lower than 100%than with pure oxygen. Consequently, it is desirable to establish apractical and cost-effective means of supplying nitrogen-oxygen mixes topatients with a regulated concentration of oxygen (e.g., 60%, 80%,etc.).

While gas companies can supply nitrogen-oxygen mixes to order inhigh-pressure cylinders, neither the cost nor the storage aspects ofsuch supply are likely be tenable for personal applications. Thus,methods and apparatus for injecting nitrogen or preferably air into thebreathing circuit have been developed so that pure oxygen is dilutedwith nitrogen to the extent desired. At the low oxygen flow rates usedin the present invention, the volumes and flow rates of the diluent gasare relatively small. A system employing a high-quality pressureregulator and a series of fixed-orifice Venturi valves that can beconfigured to entrain surrounding air and deliver the required mixtureat a fixed injection rate can suffice.

The hyperoxic gas delivery system of the present invention includesunique, non-standard shapes. The parts making up the complete assemblyin its various options are the head tent, the hood ring, the necksealring, the neck dam, the torso sealing collar, the torso securing collar,and the over-jacket/suspenders. The components of the present inventioncan be manufactured using a low-cost molding technique which uses an RTV(room temperature vulcanizing) compound. The molds allow manufacturefrom urethane. Alternatively, standard metal molds can be used.

In some embodiments, for example home users (e.g., family of an autisticchild), can be provided access to a central computer system via, forexample, the Internet on an anonymous basis to upload patientinformation and to receive recommendations for dose management (e.g.,initial dose and dose adjustments based on an oxygen dose-responsemodel). This exchange of information can be accomplished, for example,through an Internet website. As dose management is based on an oxygendose-response model/factors, this function can help to individuallyoptimize therapy. It also provides data to be aggregated and used inoxygen dose-response model and process refinement as well as submissionto medical regulatory authorities for formal recognition of specificapplications. This embodiment may also include an application for boththe computer and smart phone that will help the user schedule and recordtreatments, enter indications of healing, and store results.

In some embodiments, methods of the present may be used to treat orenhance treatment of many other conditions, including, but not limitedto other neurological conditions, other normal wound conditions, andother miscellaneous medical conditions. Examples of other neurologicalconditions include cerebral palsy, traumatic brain injury, stroke,chronic traumatic encephalopathy, amyotrophic lateral sclerosis, chronicpain syndrome, dementia other than Alzheimer's, fibromyalgia,Friedreich's ataxia, Huntington's disease, migraine/cluster headaches,multiple sclerosis, Parkinson's disease, post-traumatic stress disorder,reflex sympathetic dystrophy/complex regional pain syndrome, chronicconditions associated with stroke, and spinal cord injury. Examples ofother treatable conditions include developmental disorders such asautism spectrum disorders, Alzheimer's disease, etc. Examples of othertreatable normal wound conditions include uncompromised surgicalprocedures such cosmetic surgery, dental/oral surgery, hair restorationand removal procedures (not including transplants), hair transplantsurgery, and physical overuse injury. Examples of other treatablemiscellaneous medical conditions include chronic fatigue syndrome,glomerulonephritis, repetitive strain injury, and rheumatoid arthritis,prophylaxis against repetitive strain injuries, delayed onset musclesoreness and inflammatory disorders such as glomerulonephritis andCrohn's disease.

Accordingly, while the present invention has been disclosed inconnection with the preferred embodiments thereof, it should beunderstood that other embodiments may fall within the spirit and scopeof the invention, as defined by the following claims.

The invention claimed is:
 1. A method comprising: applying a hyperoxictherapy delivery system to a patient; administering hyperoxic gas to thepatient according to an oxygen dose-response model; and adjusting theadministration of the hyperoxic gas to the patient based upon monitoredparameters related to a condition of the patient.
 2. The method of claim1 wherein applying a hyperoxic delivery system to a patient includesputting a breathing hood assembly on the patient.
 3. The method of claim1 wherein administering hyperoxic gas includes administering hyperoxicgas based upon oxygen dosage.
 4. The method of claim 3 whereinadministering hyperoxic gas based upon oxygen dosage is performed atapproximately one atmosphere of pressure without a whole-body chamber.5. The method of claim 1 wherein administering hyperoxic gas includesproviding the patient with oxygen or other hyperoxic nitrogen-oxygen gasmixes with a fraction of inspired oxygen (FiO₂) of approximately 30% toapproximately 100%.
 6. The method of claim 5 wherein the oxygen or otherhyperoxic nitrogen-oxygen gas mix is provided at a constant pressureeffectively providing a positive end expiratory pressure in a range fromapproximately 6 cm H₂O to approximately 10 cm H₂O.
 7. The method ofclaim 1 wherein administering hyperoxic gas includes administeringhyperoxic gas approximately once per day for up to approximately fivedays per week.
 8. The method of claim 7 wherein administering hyperoxicgas includes administering hyperoxic gas for a duration in the range ofapproximately 30 minutes to approximately 90 minutes.
 9. The method ofclaim 1 wherein adjusting the administration of the hyperoxic gasincludes adjusting the dosage of the oxygen in the hyperoxic gas beingadministered.
 10. The method of claim 9 wherein adjusting the dosage ofthe oxygen includes adjusting at least one of a fraction of inspiredoxygen (FiO₂), duration, and frequency of administration of thehyperoxic gas.
 11. The method of claim 1 wherein adjusting theadministration of the hyperoxic gas includes reducing at least one ofFiO₂, duration, and frequency of administration of the hyperoxic gas inaccordance with the oxygen dose-response model, to maintaineffectiveness.
 12. The method of claim 1 wherein adjusting theadministration of the hyperoxic gas includes assessing monitoredparameters.
 13. The method of claim 12 wherein the monitored parametersare selected based upon a condition of the patient.
 14. The method ofclaim 13 wherein the condition of the patient is at least one of autismspectrum disorders, cerebral palsy, uncompromised surgical procedures,traumatic brain injury, stroke, and glomerulonephritis.
 15. The methodof claim 13 wherein the monitored parameters include scores on anevaluation checklist for autism spectrum disorder.
 16. The method ofclaim 13 wherein the monitored parameters include a gross motor functionmeasure (GMFM) for cerebral palsy.
 17. The method of claim 13 whereinthe monitored parameters include at least one of an immediatepost-concussion assessment and cognitive testing (ImPACT) score and apost-traumatic disorder check list (PCL) score for traumatic braininjury.
 18. The method of claim 13 wherein the monitored parametersinclude serum creatinine concentration for glomerulonephritis.
 19. Amethod comprising: determining an initial oxygen dose-response model fora patient based upon the patient and a condition to be treated; applyingan initial oxygen dose to the patient in an initial treatment sessionbased upon the initial oxygen dose-response model; reassessing thepatient's condition periodically; adjusting the oxygen dose-responsemodel to reflect the patient's reassessed condition; and determining anadjusted oxygen dose based upon the adjusted oxygen dose-response model.20. The method of claim 18 wherein determining an adjusted oxygen doseincludes reducing an oxygen dose within an envelope of treatmentparameter values of a fraction of inspired oxygen (FiO₂) ofapproximately 30% to approximately 100%, oxygen partial pressure ofapproximately 0.3 ATM to approximately 1.0 ATM, and absolute pressure ofapproximately 1 ATA.
 21. A system comprising: a processor; a memorycoupled to the processor and operative to store instructions executableon the processor to: determine an initial oxygen dose-response model fora patient based upon the patient and a condition to be treated; indicatean initial oxygen dose to apply to the patient in an initial treatmentsession based upon the initial oxygen dose-response model; receive datafor reassessing the patient's condition periodically; adjust the oxygendose-response model to reflect the patient's reassessed condition; anddetermine an adjusted oxygen dose based upon the adjusted oxygendose-response model.